The "cuspy halo problem" refers to a discrepancy between predictions made by certain cosmological models regarding the distribution of dark matter in galaxies and observations of their rotational curves. The term "cuspy" refers to the expectation that dark matter density should peak sharply (or "cusped" profile) towards the center of a galaxy, as predicted by simulations based on cold dark matter (CDM) cosmology.
Cold dark matter (CDM) is a theoretical form of matter that makes up a significant portion of the total mass-energy content of the universe. It is a critical component in the standard model of cosmology, particularly in the context of the Big Bang theory and structure formation. Here are some key points about cold dark matter: 1. **Nature**: CDM is "cold" in the sense that it moves slowly compared to the speed of light and has low thermal velocities.
The Calorimetric Electron Telescope (CALET) is a scientific instrument designed to study high-energy cosmic rays, particularly electrons and gamma rays in the energy range from a few GeV (giga-electronvolts) up to several TeV (tera-electronvolts). It was launched to the International Space Station (ISS) in 2015 as part of a collaborative effort involving institutions from Japan, the United States, and Italy.
As of my last knowledge update in October 2023, "Bullet Group" may refer to a few different entities or concepts depending on the context. It's important to clarify your question for accurate information, but potential interpretations include: 1. **Business or Corporate Entity**: There may be a company or organization called Bullet Group operating in various industries, such as marketing, technology, or logistics.
The Bullet Cluster (1E 0657-56) is a well-known astronomical object formed by the collision of two galaxy clusters. It is located approximately 3.8 billion light-years away from Earth in the constellation Carina. The Bullet Cluster is particularly significant in astrophysics for several reasons: 1. **Collision of Galaxy Clusters**: The Bullet Cluster is one of the best examples of a merger between two large galaxy clusters.
Baryonic dark matter refers to a type of dark matter that is composed of baryons, which are particles such as protons and neutrons that make up ordinary matter. In the context of astrophysics and cosmology, "dark matter" refers to a form of matter that does not emit or interact with electromagnetic radiation (light) in a way that we can currently detect, making it "dark.
Axion can refer to different concepts depending on the context: 1. **Physics**: In particle physics, an axion is a hypothetical elementary particle that is proposed as a solution to the strong CP (Charge Parity) problem in quantum chromodynamics (QCD). It is a lightweight, neutral particle that could help explain why strong interactions do not seem to violate CP symmetry.
As of my last knowledge update in October 2023, "Axino" could refer to a few different things depending on context. However, it's not widely recognized as a specific term or entity in mainstream discussions. Here are a couple of possibilities: 1. **Axino Technology**: It could refer to a company or product in the technology sector. There are various companies with similar names, so it would be important to have more context to identify which one you're asking about.
Abell 520, also known as the "Train Wreck Cluster," is a galaxy cluster located in the constellation of Pegasus. It was first cataloged in the Abell catalog of rich galaxy clusters. What makes Abell 520 particularly interesting is its complex structure and the evidence of multiple merging galaxy clusters within it. The nickname "Train Wreck Cluster" originates from the unusual arrangement of galaxies and their dark matter distribution, which suggests that it may be the result of a collision between several clusters.
Experiments for dark matter search are scientific endeavors aimed at detecting and understanding dark matter, a mysterious form of matter that makes up about 27% of the universe's mass-energy content but does not emit, absorb, or reflect light, making it invisible and detectable only through its gravitational effects. ### Types of Dark Matter Experiments 1. **Direct Detection Experiments**: - These experiments attempt to detect dark matter particles directly interacting with regular matter.
Johan Ludvig Heiberg (1791–1860) was a Danish historian, playwright, and literary figure. He was an influential figure in 19th-century Denmark and played a significant role in the cultural and intellectual life of his time. Heiberg is known for his contributions to historical writing, literature, and theater, often focusing on topics related to Danish history and culture. Heiberg was part of the Romantic movement and was associated with various literary and artistic circles.
Jesper Lützen is a mathematician known for his work in the field of mathematical logic, particularly in category theory and topology. He has contributed to the understanding of various mathematical concepts and frameworks.
Jens Høyrup is a Danish mathematician known for his work in the fields of mathematics education, history of mathematics, and the philosophy of mathematics. He has been active in exploring concepts related to mathematical thinking and the ways in which mathematics is taught and understood. His contributions often emphasize the social and cultural dimensions of mathematics, as well as the importance of historical context in understanding mathematical concepts.
Hieronymus Georg Zeuthen (1839–1920) was a Danish mathematician known for his contributions to various fields, particularly geometry and mathematical education. He is notable for his work on projective geometry and for his role in the development of mathematical teaching methods. Zeuthen made significant contributions to the understanding of the foundations of geometry and had an influence on the study of the history of mathematics.
Asger Aaboe is a Danish mathematician known for his work in the history of mathematics and the development of mathematical education. He is particularly noted for his contributions to the study of ancient Greek mathematics and the history of arithmetic. Aaboe has written extensively on the history of mathematics, including the influence of Babylonian and Greek mathematics on the development of modern mathematical thought. He has also been involved in various educational initiatives, emphasizing the importance of a historical perspective in understanding mathematics.
Anders Hald is best known for his work in statistics and is particularly recognized for his contributions to statistical theory and methods. He was a Danish mathematician and statistician, and one of his notable contributions is the book "A History of Statistical Concepts," which traces the development of statistical ideas over time. Hald's work has significantly influenced the field of statistics, especially in areas involving the foundations of statistical inference and design of experiments.
William Grey Walter (1910–1977) was a renowned British neuroscientist, robotician, and cyberneticist, best known for his pioneering work in the fields of robotics and artificial intelligence. He created some of the earliest autonomous robots, called "tortoises," which were simple machines designed to exhibit behavior that mimicked biological responses. Walter's work explored the intersection of biology, psychology, and technology, particularly in understanding how simple computational systems could mimic complex behaviors in living organisms.